galpy.potential.Potential.z2deriv¶
- Potential.z2deriv(R, z, phi=0.0, t=0.0)[source]¶
NAME:
z2deriv
PURPOSE:
evaluate the second vertical derivative
INPUT:
R - Galactocentric radius (can be Quantity)
z - vertical height (can be Quantity)
phi - Galactocentric azimuth (can be Quantity)
t - time (can be Quantity)
OUTPUT:
d2phi/dz2
HISTORY:
2012-07-25 - Written - Bovy (IAS@MPIA)